Sleeve type regulating valve

Abstract

The invention discloses a sleeve type regulating valve, and belongs to the technical field of regulating valves. According to the key points of the technical scheme, the sleeve type regulating valve comprises a valve body, a valve core, a valve rod and an actuating mechanism, a valve seat is arranged in the valve body, a sleeve is mounted on the valve seat, the valve core is mounted between the valve seat and the sleeve, the valve rod is arranged in the valve body in a penetrating manner, the valve rod penetrates through the valve core, a pressing ring is installed on the valve core, a balance sealing ring is arranged between the valve core and the pressing ring, an elastic sealing ring is installed between the valve core and the sleeve, and a first sealing gasket and a second sealing gasket are installed on the upper side and the lower side of the elastic sealing ring respectively. A metal material and an elastic material are adopted for sealing at the same time, complete matching can be achieved under elastic compensation of the elastic material in the high-temperature and low-temperature state, dead zones are effectively reduced, the adjusting precision is improved, the leakage amount is effectively reduced, and the leakage grade is improved.

Description

technical field [0001] The invention relates to the technical field of regulating valves, in particular to a double-seal sleeve type regulating valve. Background technique [0002] Sleeve control valves are widely used in industrial production processes, such as thermal power plants, coal chemical industry, LNG liquefied natural gas and other industries, and play a vital role in pipeline systems. The valve core is its opening and closing part, and the sleeve can It is designed into various types, such as ordinary window type, multi-hole type, labyrinth type, etc., to meet the requirements of various working conditions; the cross-sectional area of ​​the flow channel can be changed during the movement of the valve core to form a precise adjustment of the medium. It is a This kind of straight-stroke regulating valve has good sealing performance, but it has two functions of regulating and switching at the same time. It can be matched with pneumatic or electric actuators and is s...

AI Technical Summary

Problems solved by technology

[0003] (1) if figure 1 As shown, it is a pilot-operated trim structure, which can meet the conditions of high temperature, low temperature and high pressure, but the structure is complicated, the processing cost is high, and it is not suitable for low pressure conditions. The calculation process of unbalanced force is complicated, and the valve core and valve stem are not rigidly connected. Easy to surge is the biggest disadvantage of the pilot structure;

[0004] (2) if figure 2 As shown, it is a pan-sysical balanced inner part structure. Due to the material problem of the balance ring, the balanced structure of the pan-sysical ring cannot be applied to high temperature conditions. At the same low temperature, the shrinkage coefficient of the pan-sysical ring is much larger than that of the metal due to the material problem. , the size deformation is serious, even the special low-temperature sealing ring on the market cannot solve this problem, and it becomes extremely hard at low temperature, which not only cannot meet the leakage requirements, but also easily causes valve jamming, the balanced structure of the universal plug ring is only suitable for -29-200°C working conditions, even under such working conditions, there is a lot of friction with the metal, there is friction, and the service life is not long, and the internal parts of the Pansythen ring cannot eliminate the existence of the unbalanced surface. Therefore, the valve cannot eliminate the unbalanced force;

[0005] (3) if image 3 As shown, it is a balanced internal structure of flexible graphite. The balanced structure of flexible graphite is similar to that of a pan-then ring, but the sealing material is different. However, flexible graphite is suitable for high temperature and low pressure differential conditions. Due to the structural problems of flexible graphite itself, it is suitable for static sealing, but dynamic Sealed high pressure difference is easy to be blown away by the pressure, the leakage level is poor, the friction force is large, and the flexible graphite balanced structural internal parts cannot eliminate the existence of the unbalanced surface, so the valve cannot eliminate the unbalanced force;

[0006] (4) if Figure 4 As shown, it is a C-shaped ring internal structure, which is suitable for high and low temperature, high and low pressure working conditions. Due to the complicated forming process of the C-shaped ring, there are still welding problems, and the welding joint processing technology is difficult to overcome. In the case of leakage level not greater than Ⅳ level It can be used, but there is still short-term sliding friction at the moment of closing, which is prone to strain problems. It cannot meet the strict requirements on leakage, and the unbalanced area is large, so the unbalanced force is relatively large, which is not conducive to stable adjustment;

[0007] (5) if Figure 5 As shown, it is a traditional two-seat internal structure. Due to installation problems, the outer diameter of the upper and lower valve seats must be different in this double-seat structure, which leads to a large unbalanced force; Image 6 As shown, it is a two-seat internal structure. The unbalanced area of ​​this structure is slightly smaller than that of the traditional two-seat internal structure, but it still exists and cannot be eliminated. The above two two-seat structures are due to the fact that the two sealing surfaces do not have any Compensation, and in principle it is rigid contact, and it is impossible to achieve simultaneous sealing in practice, resulting in a leakage that is dozens or even hundreds of times larger than that of a single-seat valve. If the leakage needs to be reduced, it must be tested and matched repeatedly, with a long construction period and high cost; Even if the leakage requirements are met under normal temperature conditions, the sealing requirements cannot be met due to the expansion or contraction of parts at high or low temperatures during actual use. , it is only suitable for the condition that the leakage requirement is not strict

Images